The Underscan mode displays the full video frame, which reveals content on the edges that is recorded but not shown in the camera's flip-out LCD. In Overscan, the Field Monitor zooms in to the area that would be visible on most televisions. Set the Field Monitor to Underscan if your video will be viewed on a computer monitor or shown with a projector and also to look for light stands, microphones, and other unwanted objects on the edges of your shot. Set it to Overscan to see how the video will look on a television.
To switch between these two views, click the U. Scan button on the Field Monitor or press ALT+U. For more information, see the Underscan/Overscan section of the Field Monitor page.
A Little Background on "Underscan:" Back in the early days
of television, the image on their little screens shrunk as TV sets got older because the electron gun
that created the picture didn't move as well as it aged. As a result, a black border would appear around
the edges of the picture. The electron gun could be recalibrated to fill the whole screen, but that
was time consuming and costly. The solution that the TV industry settled upon was to "crank up"
the electron guns of new picture tubes to paint the image beyond the borders of the picture tube. Then,
as a TV set aged, more of the image would become visible rather than black bands appearing.
While this remedy worked, it created two problems. First, the broadcast industry coined the terms underscan and overscan and gave them counterintuitive meanings: "overscan" is the central part of the image that you can see on standard TV, whereas "underscan" is the full frame, which is visible only a production monitor. So the underscan actually shows more more of the picture than the overscan.
Second, the underscan solution has frustrated videographers and graphic designers to this day because they cannot be sure just how much of the frame will be visible on any given TV set. So they have to make sure that everything essential to scene is visible within the "Safe Area" while also taking care that nothing extraneous creeps into the overscan margin.
When the monitor is set to the Underscan mode, we recommend turning on the Video Safe Area display, which superimposes a white line that is centered on the true center of the picture that all televisions see.
To enable this feature, click the Safe button.
The safe area conventionally is the central 90% of the frame. The Safe Area Size setting in the Field Monitor menu allows you to adjust the area from 50% to 100% of the frame.